I decided to perform some tests to engrave a PCB with the fiber laser today.
Apparently, copper is very reflective and it creates a lot of heat. So far, I could not find a setting that would ablate the copper without burning the FR-4 carrier material.
But the UV-active coating from the PCB I used can be lasered away very quickly:
Great, I’ll be following. I have tried this over the last couple years since I got the fiber.
Noticed the awful smell of the epoxy layers and found them to produce gasses you don’t want to be around…
You also can’t punch holes out of it very easy with the fiber, so it’s difficult to line up (register) if you need to put it into a milling/automated drilling machine to make holes. I used my little cnc3018 for holes.
What you have etched is the negative of what a circuit would generally be… have you tried part of a circuit, instead of text.
Did you attempt any kind of registration of the part?
So you used the laminate type film and instead of masking and exposing to UV, you just let it all get exposed (100% resist coating on you PCB), then burned away the resist with the laser and etched?
Cool!
Yes, the lasered areas are where the UV-Active layer is removed, so the copper can be etched away.
Not sure, what you mean by this.
Yes, Yes! It will come.
Turns out, I remembered the used etchant wrong:
When you do this the traditional way with UV exposure, sodium hydroxide is used as the developing agent. - I didn’t do this part.
I just removed the UV-active layer with the fiber and put it in the pre-made bath in our Makerspace, which must have been Sodium persulfate - Wikipedia
I would make a crappy chemist.
I just use common household lye (powder added to water) to remove the remaining resist. Of course follow all the usual precautions with gloves and eye protection…
